10.4: Tragedy of the Commons

It is perhaps a sad sign that the most cited article in natural resource literature is one describing immanent failure at managing limited resources. Garret Hardin’s 1968 article “Tragedy of the commons” has become part of the parlance of our times, and the points Hardin raised are still the focal point of much discussion among academics and resource managers. In the article, Hardin describes how economically rational ^[4] behaviour, at the individual level, can lead to the collapse of common pool resources, that is, resources that are open to exploitation by multiple users. Contemporary examples include fisheries, forests, and the Earth’s atmosphere (in the context of greenhouse gases).

Hardin uses the illustration of cattle grazing on an open prairie to illustrate his point. Consider five herders, each with his own herd of cattle, sharing a common area for grazing. Since the grass is a renewable resource this situation can continue indefinitely as long as the rate of grazing does not exceed the grass’s growth rate. And naturally, if a rancher were to add an animal to his herd, the added animal would mean added pressure on the pasture, but since the pasture is shared by five herders the added costs (i.e. negative effects on the pasture) are split five ways, while the rancher who added the animal reaps all the added benefits (e.g. additional milk or meat). Thus, simple arithmetic tells the herder to add to his herd. Since each herder follows this same line of reasoning, each herder adds animals, and each added animal results in more pressure on the pasture. Eventually, the pasture becomes so damaged that it can provide only a small fraction of the benefits seen before the pressure increased.

This pattern, argued Hardin, will be followed in the context of any common pool resource. Even when the resource users are aware of this dynamic, avoiding a collapse is difficult. If one or two of the herders decides to forego extra animals in an effort to save the pasture, the life of the pasture might be extended, but as long as any of the herders continue to increase their herds, then eventual collapse is inevitable. Thus, a herder who is perfectly aware of the dynamics of the tragedy of the commons might not unreasonably decide to increase his herd while possible, taking what benefits he can before the resource collapses. This attitude has been seen in fishers who, knowing the fishery to be near collapse, continue to fish to draw as much income as they can before the end (see Carey, 1999).

It is worth dwelling on Hardin’s title for a moment. Hardin explained that he does not use the term tragedy to refer to how sad this situation is. Rather, he uses it in the context of what he calls (quoting Alfred Whitehead) “the remorseless working of things” (Hardin, 1968, p. 1244). In other words, the resource users are destined to collapse the resource, not because they are malicious or irrational, but because this is simply how common pool resources work. Others disagree with this conclusion, and we will discuss some additions and amendments scholars have made to these ideas. First, however, we will look at other barriers to the sustainable use of resources.